Re: Help with Hash of hashes, is there a better way?

[roboticus]

TeraMarv:

Since you're concerned about the effort of traversing the data structure and asked for alternative data structures, I have a couple of thoughts.

While it's nice to have a perfect representation of your system, it may be that your code doesn't really do anything fancy with $env, $platform, etc., and only need them in a couple of edge cases. In that case, you may want to flatten your data structure by combining the keys, allowing you to split out the parts you want if/when you need them. Something like the following (contrived) example where we need a disk usage warning report:

# Assumes top hash key is in the form:
#    hostname:platform:env
# and the second-level hash key is:
#    target
# and since the lowest level of your example is always the
# same structure, we put the values in an array:
#    [0] = total_capacity
#    [1] = current_free_space
while (my ($hostkey,$targets_href) = each %{$stuff}) {
   # *This* report doesn't care about prod/dev or OS, it's
   # just to warn about disk space problems, so only need
   # $host...  Other reports may want other bits
   my ($host,undef) = split /:/,$hostkey;
   print "\n*****\n* $host\n*****\n\n"
   .     "FreeSpc  %Free Target\n"
   .     "-------- ----- -----------------\n";
   while (my ($target,$cap_href) = each %{targets_href}) {
       my $pct_free = $cap_href[1] * 100.0 / $cap_href[0];
       if ($cap_href[1] < $warn_pct * $cap_href[0]) {
          printf "% 8u %5.3f %s\n",
             $cap_href[1], $pct_free, $target;
       }
   }
}

--roboticus